Plants obtain the water needed for photosynthesis primarily through their roots, which absorb water from the soil and transport it to the leaves.
Here's a breakdown of the process:
-
Absorption by Roots: Plant roots, particularly root hair cells, are specialized for water absorption. Root hair cells have a large surface area and thin walls to maximize the uptake of water from the soil.
-
Transport Through Xylem: Once absorbed, water travels through the plant's vascular system, specifically the xylem. Xylem vessels are like tiny pipes that transport water and dissolved minerals upwards from the roots to the stems and leaves. This upward movement is driven by a combination of factors, including:
- Transpiration: The evaporation of water from the leaves creates a "pull" or tension that draws water upwards through the xylem.
- Cohesion: Water molecules are attracted to each other (cohesion), allowing them to move upwards as a continuous column.
- Adhesion: Water molecules are also attracted to the walls of the xylem vessels (adhesion), which helps to counteract the force of gravity.
-
Delivery to Leaves: Finally, the water reaches the leaves, where it is used in photosynthesis. During photosynthesis, plants use water, carbon dioxide, and sunlight to produce glucose (sugar) and oxygen.
In summary, plants' roots act as the entry point for water, and the xylem serves as the transport network to deliver water to the leaves for the vital process of photosynthesis.
